Modified cotton



- cloth.

Patented Mar. 14, 1933 um'rso \STATES PA E T- OFFICE;

cmnnns r. eonn'rnwunor; iroun'r memoir 'rownsmr, ALLEGHENY scum,rmsnvmm, assrgnon, ZBY mnsnn assreimmrs, 'ro 'rnx-rrrn mourn-nayoonroiwrzon, A CORPORATION or nnmwm aroma-Inn co'r'ron Io Drawing.Application med June 4,

ture.

This application is akin to my co-pending application, Serial No.476,441, filed August 19, 1930, (now abandoned) and to two otherapplications Serial Nos. 542,106 and 502,107 filed on even dateherewith, for process of strengthening cellulose.

An object of this invention is to rovide a modified cotton fibre which,by c ange of structure, becomes a new cellulose fibrer;

A further object of the invention is to produce a modified cotton fibrewhose strength is far greater than that of the natural or otherwisemodified cotton.

The value of this fibre lies in its great strength, which is farsuperior to that of other known cottons or modified cottons. Theprocesses employed consist in the treatment of cellulose, particularlycotton, with swelling agents such as caustic soda, under conditions suchas hereinafter specified.

This treatment may be followed by heating the cotton in a soap or othersolution to en hance the strengthening efiect.

The novelty of this invention is proved by X-ray analysis, the new fibregiving an X ray difiraction diagram that is different from that of anyother known cotton or modified cotton.

The new fibre is made from natural cotton conveniently described in theform of yarn,

but this is intended to embrace the use of cotton in other forms, suchas loose fibre or lhe new fibres-are very difierent in outwardappearance from natural cotton fibres,

.but retain approximately the same dimensions.

They resemble, in appearance, other modified cottons, particularly thoseproduced by ordinary memorization, but they are tundra mentallydifferent in structure within the individual fibres from natural,mercerized or other known modified cottons.

There are numerous grades of cotton, and so far as known, they can allbe converted to the new type of fibre. Comparable results 1981. SerialNo. 542,105.

, Therefore, it is not intended to limit this application to cotton ofany specific gain in strength.

It has been found by various investigators, by means of X-rays, that thenatural forms of cellulose have characteristic internal forms ofstructure. The present knowledge of the subject indicates that allcelluloseconsists very largely,'3if not entirely, of elongated particlescalled micelles. These particles have a very definite type of structure,which is commonly described as crystalline.

In some fibres, particularly in natural cotton, the micelles arearranged in irregular spiral forms around the fibre axis, an arrangementwhich is not conducive to the greatest strength of cellulose.

In other celluloses, such as ramie, the micelles have grown naturally inthe plant in %uite perfect parallel arrangements, and such bres areusually very strong.

The natural plant fibres each have characteristic sizes, shapes andother physical properties which are peculiar to them, as well as theform of internal structure.

Treatment of these natural fibres with chemicals, notably themercerization of cotton, may change the external ap earance andotherwise alter the character of libres to some extent. But as far asknown, a 10h treatments have not greatly influenced the internalstructural arrangements of the individual fibres.

From the X-ray studies, it has been found that there is a closeconnection between the strength of the cellulose of a fibre and thedegree of parallelism of its micelles. In gen eral, the higher thedegree of parallel orientation, the higher is the strength, butparticularly when the comparison is made within a class. That is to say,cotton with cotton,

viscose rayon with viscose rayon, cupramf monium rayon with cuprammoniumrayon.

This has been particularly well exemplified by- Professor George L.Clark, of the Department of Chemistry, University of Illinols, in a.paper a ari ng in Industrial and Engineering gh mistry, May, 1930,

volume 22, page 474 et seq. and considering especially cellulose'inother forms than cotton This article deals at length with theorientation of the micelles in cellulose, and- Figure 8 in said paper isilluminative.

For example, certain strands of rayon of inferior strength show a higherrandom arrangement of the micelles, while others made from the samematerials, but with greater stretching and tensioning, show the micellesmuch more nearly parallel, and

have much higher strengths. (See Figures 16, 17, 18, 19 and 20 of theabove article).

. And while these materials are outwardly similar in form, they arereally different materials with different properties, owing to theirdifferent internal structures.

The new fibre forming the subject-matter of this invention has a similarX-ray dia gram to that of the strongest rayons, indicatm a similarity ininternal structure, but it di ers from rayon in that'it has never been,

through a state of dispersion in a li uid as in rayon manufacture. Ithas instead can converted directly from natural cotton bsuitablemanipulation and treatment in t e fibrous form with chemicals.

It is, of course, to be understood that. parallelism of micelles is notthe only important factor in the strength of cellulose. Its strengthdepends fundamentally upon theattraction for each other of the atoms,molecules and other, particles of which the substance is composedaAccording to the present state of knowledge, it is supposed that themore perfect parallel'arrangement of micelles causes a closer packing ofthese structural units and promotes the attraction between them.

The extra strength is, therefore, partly due to the closer associationof the mlcelles or to the development of new points of attractionbetween them.

The novel nature of the new fibres is shown by both the increasedstrength and the X-ray (fliagr'am, which indicatesthe new structuralorm.

In order to illustrate and define the character of this new fibre, X-rayanalyses were made, covering untreated natural cotton, commercialmercerized yarn, and yarn treated in accordance with the presentinvention.

For the sake of examples, in natural E tian cottonthe double strandstrength 6 60/2 yarn measured 1.53 pounds in a dry atmosphere but 1.75with standard humidity with a slightly gram of its-fibres showed theusualrandom conditions, the 'X-ray I difl'raction arrangement ofmicelles for natural cotton. Y

Thesame yarn, after bemg commercially mercerized, measured-2.07 poundsand its .fibres shows a slightly improved diagram I eater degree ofparallel arthe following procedure was used: Two-ply cotton. of theconstruction commonl known as mercerizmg-twist was immerse in dry skeinswithout previous boiling-out) in a" 35% so ution of caustic sodacontaining suitable amount of wetting agent for use in caustic sodasolution.

It was allowed to shrink freely in this solu- I tion. After a thoroughsoaking the yarn was squeezed and put on rollers in a frame while stillcontaining the caustic. It was then stretched to a proximatel its ori allen h, and furt er stretche while was in wit cold water to approximately4% beyon its original length.

' The yarn was neutralized with acid while I in the stretched conditionwashed in the loose form, stretched again, and dried as usual with heat.While still in the stretched condition it was boiled for fifteen minutesin a 2% solution of soap, then washed and dried while still held taut.

,Retaining approximately. its original dimensions means that the fibresin a 'ven yarn appear in the modified form at practicall the originallength; that the shapes and imensions of the crosssection are somewhatchanged; .but that there is no appreciable amount more or less fibresubstance in a cross section. superficially the fibres would appear tobe of the same size as beforetreatment.

This invention is not limited to cotton prepared with caustic soda butmay include that repared by other alkalies or swelling agents orcellulose; it may also include modified cotton of the characterspecified, produced by heating in other colloidal solutions than soapparticularly so-called we agents an some salts of organicacids, incuding or nic salts or soaps such as those made wit the ethanolamines andother organic bases.

Experiments and tests have-fprovediithat there isa suflicient conversionof fibres part an unusual strength to inns and to cause them to show thetypical dia am for highly oriented micelles when'suitagly analyze byX-rays. These eflects can be taken as proof that the cotton has beenvery completely converted to a new and more valuable fibrous'material.

Throughout this application and claim where the word oriented or thelike is used, it will be understood that the sense of the word must beconstrued as meaning an arrangement parallel with the fibre axis)? Inthe article above referred to as appearing in the Industrial AndEngineerin Chemistry, Figure 13 shows an X-ray di fraction diagram ofordinary cotton, while Figure 2 therein shows an X-ray diffractiondiagram of native ramie having a high degree of orientation of miscellesarallel to the fibre axis. The new article 0 manufacture claimed herein,namely a modified cotton fibre of high strength, may be produced fromordinary cotton and has given an X-ray diffraction diagram practicallyidentical with the ramie diagram shown in Figure 2, of that I article.

Of course, the specific structures mentioned herein are not to be takenas limiting this invention in' any way, and it is to be understood thatvarious modifications and changes in the method of treatment may beemployed without departing from the invention herein set forth andhereafter claimed. v

The invention is hereby claimedas follows: 1. A modified cotton fibreretaining approximately its original dimensions and char acterized-bythe X-ray 'difl'raction diagram of oriented cellulose. new article ofmanufacture comprisin .a'modified cotton fibre having its miscellesapproximating perfect orientation and havin a tensile strength fargreater than that o the natural or otherwise modified cotton.

3. A modified mercerized cotton fibre re- .tainin approximately its oriinal dimensions and .c aracterized by the -ray difiraction diagram ofhighly oriented cellulose.

4. A new article of manufacture com rising a modified mercerized cottonfibre aving its miscelles' approximating perfect orientation and havin atensile strength far greater than that of the original mercerizedcotton.

In testimony whereof I have signed my name to this specification.

CHARLES F. GOLDTHWAIT.

